Bacteria of genus Tepidimonas are bacteria which are gram-negative, strictly aerobic, oxidase- and catalase-positive, rod-shaped and slightly thermophilic bacteria.
The inventors of the present disclosure anteriorly sampled the water samples of An-tong hot spring in Hualien County, Taiwan. Then, bacterial strains in the water samples were isolated and purified to obtain a novel bacterium of Tepidimonas named Tepidimonas fonticaldi sp. nov. Extracellular proteins secreted by Tepidimonas fonticaldi sp. nov. have excellent effects for binding metal ions, and are not influenced by environmental conditions, such as high temperature, high pressure, or pH value. Therefore, the extracellular proteins secreted by Tepidimonas fonticaldi sp. nov. can prevent metal salt scale, especially calcium carbonate, formed in boiler equipment, underground pipelines, geothermal wells, industrial wastewater or hard water, to keep the function of the machines and reduce the operating time and cost.
However, the growth and self-protein metabolizing rate of bacteria of genus Tepidimonas are slow and it causes that the protein is hard to be obtained. Therefore, a novel culturing medium and a novel culturing method are needed.